This invention relates to a socket having a contact element which is to be elastically compressed to an electrical part so as to establish electric contact in connection with the installation of a semiconductor integrated circuit chip (IC) by inserting a molded IC package such as for example, a socket for IC chip use.
As the IC package has become thinner and smaller in size in recent years, and as applications for surface installations have increased, the quality of the product has become more difficult to control. This situation makes for testing and the elimination of unacceptable products very important.
With this fact in mind, standard testing (such as a heat resistant test that is called a burn-in test) of IC packages including IC packages for surface installation is performed in which IC packages are placed in a testing furnace so as to distinguish the good from the bad products.
One type of socket as known in the prior art used for such testing is the so-called ZIP (zig-zag in-line package) socket 10 which is shown in FIGS. 9 through 11. An IC package 2 which is installed on this ZIP socket is designed so that the loads 5a and 5b extending from the bottom of the molded resin portion of the IC 2a are in two rows for insertion into the socket 10 as clearly shown in FIG. 9. The contact element 4 of the socket is formed as a single metal piece which is bent back at its lower end with the bent part being inserted into the base of the socket.
For installation of the IC package, the IC package 2 is faced in the perpendicular direction and the leads are inserted into the respective lead insertion holes 3 corresponding to the various leads. Each lead is inserted between the mutually facing elastic holding parts 4a and 4b of the pin-shaped contact element 4 that has been positioned in the lead insertion hole 3 so as to elastically hold the lead as shown in the drawings. An action opposite to that described above is carried out in order to withdraw the IC package 2 from the socket.
It has been found, however, that the aforementioned ZIP socket has certain shortcomings. In an automated operation for insertion and withdrawal from the socket, the IC package may be positioned sideways on the tray because of its shape which requires that the packages have to be repositioned in the perpendicular (vertical) direction before they are inserted into the socket with the consequence that the steps required for automation become more complicated. Additionally, the leads 5a and 5b of the IC are pushed into the gap between the mutually facing holding parts 4a and 4b thereby separating these holding parts and giving rise to the possibility of the leads and contacts being deformed.